With the rapid development of display technologies, touch screen panels are widely applied in people's daily life. Currently, in-cell touch panels are very popular with the major panel manufactures as the touch components are embedded inside the display panels, which can not only reduce the overall thickness of modules but also significantly reduce the fabrication costs of touch panels. Therefore, driving methods for the in-cell touch panels are a research topic of much concern in the touch panel area.
A driver circuit in a conventional in-cell optical touch panel is a multi-stage driver circuit comprises driver circuits for respective stages for implementing the touch function; the signal at a touch signal sensor of the driver circuit at each stage is read via a touch signal sensing line, and the position of a touch point is determined by analyzing the signal at the touch signal sensor.
The main drawback of the driver circuit for the conventional in-cell optical touch panel lies in that: signals output at touch signal sensors for different driver stages will interfere with each other if the touch signal sensors of the driver circuits for the stages are connected to the same touch signal sensing line, thereby jeopardizing the accuracy of touch signal detection of the touch panel; on the other hand, the wiring area in the touch panel will be increased if an individual touch signal sensing line is configured for each touch signal sensor of individual driver stages.